1. Field of the Invention
This invention relates to fireplace fronts and more particularly to an improved heat saving fireplace front employing a concealed fireplace door of improved design that seals the front of the fireplace when in its closed position and a vent mechanism that provides an independent air supply to the fireplace when the door is closed.
2. Description of the Prior Art
With the increased cost of home heating fuels, more attention has been directed toward the possibility of heating a home by means of a conventional wood-burning fireplace. A conventional fireplace, however, is extremely inefficient in heating a home.
One problem with most conventional fireplaces is that the open flue in the fireplace acts as an open window, and the strong updraft in the flue draws warm air from the room and the heated air in the fireplace up the chimney and out of the house. With an air flow pattern of this nature, there is no convection heating at all and there is even a heat loss, due to the fact that furnace-heated air in the house is drawn into the fireplace and discharged from the house through the chimney.
This heat loss may be sufficiently offset to produce some net heating effect for the room by the radiant heat produced by the burning fire. The convection heat loss, however, minimizes the net heating effect produced by the radiant energy. Moreover the net heating effect is present only when the fire is burning brightly and turns into a net heat loss when the fire begins to die out.
Since most fires are permitted to die out at night, when the homeowners go to bed, the flue is left open all night so that the smoke from the fire will be vented from the house. The problem this produces is that once the fire ceases to burn brightly, the radiant heating effect produced by the fire diminishes, but the flue continues to act essentially as an open window drawing warm air from the room upwardly and out of the chimney.
As a result, the use of a fire in a conventional home or other such dwelling produces an overall net heating loss for the dwelling, notwithstanding the fact that a substantial amount of wood has been blazing brightly in the fireplace, at considerable expense to the owner of the dwelling.
Another problem with conventional fireplace design is that the heated room air drawn into the fireplace creates a pressure drop inside the room, and this pressure drop is balanced by the flow of cold outside air into the dwelling through cracks around windows or doors or the like. Thus, although the radiant heat from the fireplace may warm the room in which the fireplace is located, the outside draft produced by the fireplace will cause a chill in the other rooms of the dwelling. In a home that is particularly well insulated such that drafts are minimized, the fireplace either will not draw at all, and hence the fire will burn poorly in the fireplace, or the fireplace will draw air from beneath an outside door. In wet weather, when snow or water are present on the outside of the door, the cold draft under the door can actually suck the water under the door and into the dwelling, thus causing a mess on the inside floor adjacent the door.
One method heretofore developed for improving an air supply to a fireplace is to provide a separate air supply to the fireplace by an air supply drawing air from another room or from a vent outside the building. This type of air supply, however, does not eliminate the heat loss problem, and it does not eliminate air-draft from the room into the fireplace. It merely provides an improved air-draft that facilitates the burning of the fire.
Fireplace doors, as such, are known, as are concealed fireplace doors. Some fireplace doors also have been designed to seal off the front of a fireplace, thereby presumably cutting off all air to the fireplace and extinquishing the fire.
One object of the present invention is to provide a fireplace front that reduces convection heat loss and cold air drafts in a building resulting from air drafts from the room into the fireplace, while still permitting the fireplace to burn with an ample supply of fresh air.
Another object of the present invention is to provide a concealed fireplace door assembly that is easy to maintain, install and remove.